I gotta ask......how many people have actually cut/abandoned their ground tackle? Under what circumstances? I suspect it's extremely rare, and even then most likely cause is windlass died and ground tackle was too heavy to hoist by hand.
That said, one of SF Bays best anchorages was adjacent to where Weebles was moored for 20 years. An ex-Naval Station, there was a submerged cable connected to Yerba Buena Island. Once or twice per year someone would hook it. Most figured out how to retrieve after an hour of head scratching but I suppose there are a few anchors there.
Another related story. My first Willard - a Willard 30 - had a plow. We anchored off the corner of Angel Island before headed to thr Delta next morning. A decent current came through and we dragged at least 75 feet, maybe more (God bless plow anchors - good riddance). When we hauled anchor, we had not one but two additional anchors that had been abandoned, including one fairly new and large Fortress that I gave to a friend. Was a PITA to have two anchors with rode attached while drifting.
I know it happens, but don't know anyone to whom it has actually happened. I keep an angle grinder because they are handy. But if I were to need to cut a chain rode, I'd probably tether a float and leave the whole thing - my 275 feet of chain is terminated in the anchor locker with 10-feet of 3/4" nylon 3-strand so a knife is the right tool. Half a rode is sort of useless anyway.
Peter
Peter